Gas or vapor discharge device



p 1932- R. D. MAILEY GAS 0R VAPOR DISCHARGE DEVICE Filed Oct. 25. 1928INVENTOR HIS ATTORNEY V Patented Sept. 20, 1932 UNITED' STATES PATENTOFFICE no'z n. EAI EY, or EAST ORANGE, NEW JERSEY, ASSIGNOR 'ro GENERALELECTRIC vnron LAMP comrnnr, or HOBOKEN, NEW JERSEY, A conronnrron onNEW JERSEY- GAS OR VAPOR DISCHARGE DEVICE Application filed October 25,1928. Serial No. 314,929.

The present invention relates to gas or vapor electric dlschargedevicesand methods of operating the same. The lnvention relates moreparticularly to gas or vapor electrio discharge lamps having a gas orvapor filling of component parts which cooperate to give the lampuniformity durlng the life of the lamp bothin operating characteristicsand in the color lamp.

The main object of the'present invention is the production of anelectric gaseous discharge lamp operable on the usual commercialcircuits of 110 or 220 volts. For use on direct current a lamp embodyingmy 1nvention is provided with an anode and a hot cathode such as afilament of pure tungsten or thoriated tungsten, or of the type whereinan oxide coated nickel electrode body s heated by such afilament. In anembodiment of my invention for use on alternating current I use twoanodes and a similar hot cathode, connected across an alternatingcurrent source in a similar manner tothe well known Cooper Hewittalternating current rectifying lamp. In both said embodiments, the gasfilling comprises a mixture of gases having low average atomic weight,for example, helium 85-95% and neon -570 substantially, wherein one ofsaid-gases, the

of the light emitted from the major component, supports electricconduction, and the other emits its characteristic radiation byexcitation by collision, whereby the lamp has the desired radiationcharacteristic, in this case that of neon. Because of the low averageatomic weight of the gas filling deleterious disintegration of theelcctrodes and other partsofsuch lamps which are bombarded by positivecarriers is reduced and maintained at a minimum.

Various other objects and advantages of the invention will be obviousfrom the fol lowing particular description of forms of discharge devicesembodying the invention or from an inspection of the accompanyingdrawing, and the invention also consists in certain new and novelfeatures of construction and combinations of parts hereinafter set forthand claimed.

device envelope,

In the accompanying drawing Figs. 1 too somewhat diagrammaticallyshowfor purposes of illustration in vertical elevation electric resistorheater is used in'association' with a body of m'aterial such as anoxide, hydroxide or carbonate of metal'such as calcium, magnesium,barium, strontium, lithium, thorium, or the like, which material iscoated over the resistor or is otherwise mounted in operative relationthereto. The gases or vapors used for sustaining a discharge are therear gases such as neon, helium, argon, etc., mercury', the vapors ofsodium, lithium, potassium, calcium and the like or mixtures thereof. Ina gaseous discharge device for example, when current is passingtherethrough, movement of electrons and atoms and molecules thereinresults in bombardment of the several parts of the device by the ionsand electrons which are in the gas or vapor space. The ions of certaingases are of such mass that-the bombard ment of solid parts of thedevice thereby results in the breaking down of those parts and indeleterious effects on the device.'- Such blackening of the transparentwalls iof the caused by sputteringof the electrodes through positivecarrier bombardment and the depositing of the sputtered. off parts ontothe envelope wall. The envelope walls themselves are also bombarded andparticles thereof. sputtered and in such cases decomposition of thematerial of'the wall takes place with the resultant freeing ofdeleterious gases into the envelope space.

The results of such effects are reduction of the efficiency of theoperation of the device or the complete 'incapacitating thereof throughchange of operating characteristics, or through the prevention ofpassage of de sirable radiations through the device envelope by suchablackening or darkening by sputtered material.

Some vapors and gases however, have ions whose mass orweight isconsiderably less than that'of others and these are most desirable forcarrying current through the de-' vice. It is not always the case,however, that gaseswhich have comparatively low weight or 'mass havedesirable radiation characteristics. I have found that certain gasesorvapors of comparatively high weight or mass have desirablecharacteristics of radiation and further that the radiations from suchgases or vapors will predominate over those of certam other gases orvapors even when they are present w1th other gases or vapors 1n onlyvery small amounts. I have further'discovered'that there are certaincombinations of gases such, for example, as a combination or m1xture oftwo gases in which one having ions of comparatively large mass or weight'can be used in very small proportions with the other having ions ofcomparatively low mass or weight in correspondingly great proportions. Ihave further discovered that gases or vapors can be chosen in the abovesaid relationwith the further relation that the gas having the greatermass or weight and the number of its ions over those of the heavierweight gas contributes to the efli-:

ciency in the transmission of radiation producing energy to said heaviergas. A particular example of a combination 0 gases according to theabove statement of he invention is a mixture comprising about 95% heliumand about 5% neon. The weight of the helium ion is so low that adischarge device having electron emissive material of the substancesabove noted will have a com-' paratively long and useful life. On theother hand the neon, whose ions have comparatively large mass or weight,is present in sucha comparatively small amount and thepercentage of neonions present is so small that bombardment of the electron emissivematerial by ions thereof is so comparatively infrequent that theoperative life oat the device is not materially afiected. Further, whenhelium and neon are used in .a discharge device in the amounts abovestated visible light and other radiations from the neon greatlypredominate over any radiations which may be produced from the helium. Aspecific example embodying the purposes and advantages of the inventionabove noted or otherwise apparent comprises a sealed envelope of glassor quartz having the multiplication of current carriers.

a solid anode therein, a. filling comprising on the order, of to heliumand 10% to 5% neon and a cathode which consists of an electricresistance heater having posit1oned in operative relation thereto ormore particularly, formed as a coating thereover, alayer or layers ofbarium oxide. connected to a suitable source of current,

-- alternating or direct,'of a voltage suflicient to produce a dischargetherethrough, radiations characteristic of the neon will be pro duced,the helium will operate as the main current carrying medium and the neonwill serve as the main light producing medium. The barium oxide underthe influence of the electric heater cathode will serve as a prolificsource of electrons which will be accelerated through the potentialgradients in the discharge space and willbombard particularly the heliumatoms and 'ionize them and cause In a device of this kind having adischarge distance of about 18 inches in a tubular envelope of about 1mch in diameter and with 300 'volts alternating current supply and withvapor ressure of about 3 to 10 mm. of mercury, he device will operatefor more than 6000 hours. V

In Fi 1 is illustrated a direct current lamp em odying the invention inwhich the longitudinal envelope 1 has sealed thereinto at one end theanode 3 which is conne'cted to the lead 5 for connection to thepositivejside of a source of direct current. At the'o posite end of said envelopeis mounted t e cathode, shown more in detail in Fig- 6, comrising theresistor v6, connection to which is made through the leads 8 and 10sealed through said envelope .1, and the cylindrical shield 12 of ametal such' as nickel, iron, tungsten or other suitable material,mounted about said resistor 6 and having upon its outer surface acoating 13 of an oxide, a hydroxide or a carbonate of a metal such asbarium, or other electron-emissive material. Connection is made fromsaid electrode 12through thelead 14 to said resistor 6 by way "of saidlead 10 at a point outside said envelope 1. Said lead 10 is alsoconnected through the resistance 16 and the in ductance 18 to thenegative supply main-20. Connection is made from the other side'of saidresistor 6 through said lead 8, switch 22 and adjustable resistance 24to said main 5.

In Fig. 2 is illustrated an alternating current rectifying lampcomprising the sealed envelope 30 having sealed thereinto at one end thespaced apart anodes 32 and 33 which are connected respectively throughthe resistances 35 and 36 to opposite endsvof the transformer secondary38 which is in operable relation to the primary 40. At the end of saidenvelope 30 opposite from said anodes 32 and 33 is mounted a hotcathode'structure the heater 42 of which is connected through When theleads 44. and 45 to spaced apart intermediate points on said secondary38. Positioned about said cathode-heater 42-is an activated slecveorcathode 46 similar to the corresponding part 12 of Fig. 1. This element46 is connected through the lead 48 to said conductor 45. at a pointoutside the envelope. v

In .the embodiment of the invention illustrated in Fig. 3 the closedenvelope 130 of glass, quartz or other suitable material has sealedthereinto at one end the spaced apart anodes 132 and 133 which areconnected is a through the resistances 54 and 55 respectively toopposite ends of a transformer secondary 56 ,which is inoperablerelation to the transformer primary 58. At the end of said en- Telope130opposite from said electrodes 132 and 133 is mounted the hollowcylindrical cathode 60 which is of, a material such as pl'atinum,nickel, iron, tungsten or other suit- I lead 68 to said conductor 62.

, able material which has over its outer surfaces a coating of an ox1de,hydrox1de, or

carbonate of a metal such as calcium or 62 through'the inductance 64 toa midpoint on said secondary 56. About said electrode 60. is positionedthe cylindrical shield 66 which is of iron, nickel, tungsten or othersuitable material and is connected through a Positioned within saidcylindrical electrcde60 is the resistance heater 82 of tungsten,molybdenum or the like which is connected through the 5 leads 84' and 85to a coil 86 which is in position to be energized through said primary58.

In Fig. 4 is shown a sealed envelope 90 having mounted therein, one ateach end, the hollowcylinders 92 and 94 ofmetal such as iron, nickel ortungsten each of which has on either-or both of its surfaces'a coatingof an oxide, hydroxide or carbonate of a metal such as barium, strontiumor, calcium. 5 Within said cylinders 92 and 94 respectively,

are mounted the heatingresistors 96 and 98 respectively, resistor 96being connected through'the conductors 100 and 102 to the ends of a coil104 mounted in operative relation to a transformer primary 106. In likemanner the resistance 98 is connected through conductors 108 and 110 tothe coil 112 which is also in operative relation to said-primary 106.Connection is made from the cathode 5 92through the conductor 114,ballast resistance 116, to one end of a transformer secondary 118 theother end of which secondary is connected through conductor 120 and resistance 116, to the cathode 94. Connection is also made from cathode 92to'lead 100 and from cathode 94 to lead'llO, if desired.

- In Fig. 5 illustrated a closed envelope 130 which has mounted at oneend thereof the two. anodes 132 and 133 which connect through theresistances 136 and 138 respec-' barium and which is connected byconductor tively to opposite ends of the transformer secondary 140 whichis in operative relation to the transformer primary 142. At the end ofsaid enve ope 130 o posite'said anodes is mounted the ollow cylinder 144which is of metalsfich as iron, nickel or, tungsten and which has overeither or both of its surfaces. .a coating of anoxide, hydroxide orcarbonate of bariumor calcium or the like.

tiverelation tosaid inductance 148 for the,

inovmg of said switch 154 into the open circuit position by saidinductance 148 when the latter is energized! About said electrode 144 ispositioned the sleeve 160 of metal such as nickel, iron or tungstenwhich is connected through the lead 162 to said conductor 146. A heatingresistor 164 mounted withinsaid cylinder 144is connected to thetransformer secondary 166 through the leads 168 and 170.

In the envelope of the devices'illustrated in- Figs. 1 to 5 there isprovided an atmosphere of gas or vapor such as one of the rare gases,mercury, caesium .orother suitable gas or vapor, or a mixture of some'ofthese. A preferred embodiment of the invention is any one of thedischarge devices illustrated in the drawing and herein described withan. atmosphere'comprising about 90% helium and 10% neon.

In the use and operation of, the device and apparatus of Fig. 1 a directcurrent potential is applied from the leads 5 to 20 across the anode 3and cathode 12 through the inductance 18 and resistance 16 which serveto stabilize and regulate the current flow. Said cathode 12 is broughtto an electron emitting condition by heat supplied from said resistor 6which is connected on one side to said main 20 at a point between lead14 and resistance .16 and on the other through the switch 22 andresistance 24 to said main 5.

Preferably said resistance 6 is maintained.

energized during operation of the device to keep said cathode element 12heated and in an electron emitting condition but switch 22 may be openedafter the starting of discharge operation incertain cases where currentpassage through element 12 keeps that element in a sufiiciently heatedcondition to maintain electron emission therefrom. It is to be un-'derstood that said resistor 6 can be heated by oxide is applied as suchin the form of a paint with water, zapon, cellulose or varnish as thevehicle, or the oxide coating is obtained by applying a coating of thehydroxide or carbonate which-is decomposed by heat to leave the oxide onthe electrode.

In the use of the device said resistor 6 is utilized to heat theelectrode 12 and the oxide coating 13 on electrode 12'to bring it to anelectron emitting state. These electrons will be emitted into the spacein the device in which there is a potential gradient and willbeimpelled-toward said anode '3 and be discharged thereat, therebyefi'ecting current flow in the device. Further, in their movement acrossthe space the electrons will be accelerated and they will collide withgas or vapor atoms or molecules and thereby transfer to these atoms ormolecules energy which The device'of Fig. 4 is for use on menial-- ingcurrent and for conductin the currentm causes them to emit radiations inthe visible and in the invisibleranges.

The operation of the device and system of Fig. 2 is similar to that ofFig. 1 as regards the function of the cathode. The device of this figureis for use on alternating current and is adapted for rectifyingalternating current according to the functioning and manner of operationof the Cooper Hewitt rectifying lamp well known in the arts. Theresistor 42 is energized from an intermediate section of the transformersecondary 38 which is connected thereto by said leads 44 and 45. Theelectrode 46 is connected to an intermediate point on said secondary 38through lead 48 and oneof said leads 44 and 45.

. The device of Fig. 3 functions somewhat similarly to that of Fig. 2except that a separate energizing coil 86 positioned in operafiverelation tothe primary 58 is connected across the resistor 82'to supplyheating current thereto. Connection is made from an intermediate pointon the secondary 56 through.

the ind-uctance64 to said electrode 60 and-to the cylindrical shield66,, the ends of said secondary 56 being connected through resistances54 and 55 respectively-to anodes132 and 133.

both directions between sai distant,electrodes 92, 94. During alternatehalf cycles of current flow resistors 96 and 98 serve to maintain theelectrodes 92 and 94 in cathode condition by continuous energization ofthe oxidecoatings thereon to keep them in the electron emitting state.current will flow alternately from opposite During operation in the caseof the device of Fig. 1, in some,

cases discharge producingcurrent flowing through said electrodes 92 and94 will be suflicient to heat the metal oxide coatings thereon andmaintain them in the electron emissive condition through the zero point-of alternations of current flowing therethrough, the heaters then beingunnecessary after a discharge has been initiated.

The device of Fig. 5 is similar to that of Fig. 3 but includes meanscomprising inductance 148 and switch 154 for producing a high voltagesurge across the lamp to start it into operation, in cases wheredesired. In the operation of the starting means, before currentcommences to flow between the electrodes of'the discharge device andwhensaidprimary 142 is properly energized, current will. flow from themidpoint of said secondary 140 through the lead 150, inductance -148,switch 154, resistance 153, lead 152, resist ance 155, which is theheater element ,of thermostat 159, back to the secondary. The currentflowing through the circuit just described is insufiicient to open themercury switch 154'and the heating of the resistance 155 continues for apredetermined time, that is, the time it will take the heater resistance164 to bring the oxide coated cathode 144 to a temperature at which itwill operate efliciently as a cathode. During this interval thebimetallic member 157 of the thermostat 159 is affected by the heat fromthe resist-ance 155 and in forty-five seconds, say, the bimetallic barwill deform and come into contact with ;ance 155 and thereby increasingthe current through the circuit to energize the inductance 148' to avalue sufficient to attract the armature 156 on the mercury switch 154,thus pro- ,ducing a sudden break in the current flowing.

through said part of said secondary 140 whereby there is produced astatic discharge from said anode 132 and said cathode including thecylinders 144 and 160. In the meantime said resistor 164 has beenenergized from said secondary 166 and the oxide coating on .fsaidcylinder 144 brought to the electron emissive state. Such a. highpotential discharge between the cathode and the anode will .startcurrent flow from the anode to the cathode because potential differencehas been maintained from the beginning between said electrodes. Uponcommencement of regular discharge current flow through said cathode saidinductance 148 will be maintained in the energized condition and willhold said switch 154 in the open circuit position.

While.I have described the invention in" quantity of a material having are ucing etfeet on the oxides, such as potassium, magnesium or carbon,whereby there is maintained a continuous supply of electron emittingmaterial on the cathode, as well as the desired purity of the gas whenneon alone is used, or of the components of a mixture such as neon andhelium when that mixture is used.

It is to be understod that while I have described the invention asapplied to a neonhelium lamp the elements in combination are applicableto lamps in which one gas alone is used as the radiation and currentcarrying material. i

In the claims the term gas has been freely used, and is intended tocover vapor as well as gas.

I claim as my invention 1. A gaseous-discharge device comprising anenvelope, electrodes therein, one of which is adapted to emit electronswhen heated, means for heating said electrode, and a mixture of heliumand neon therein, the helium constituting at least of said mixture.

2. A gaseous discharge devicecomprising an envelope, electrodes therein,one of which is adapted to emit electrons when heated, means for heatingsaid electrode, and a mix-. ture of helium and neon therein, the heliumcomprising substantially of said mixture.

-3. A gaseous discharge device comprising an envelope, electrodestherein, one of which is adapted to emit electrons when heated, meansfor heating said electrode, and a mixture of gases within said envelopein combination with means for initiating a discharge through said deviceand means for delaying the operation of said means for initiating adischarge until said electrode has reached an operating temperature.

trodes.

means for heating said electrode, and a mix ture of gases therein, saidmixture having a low average atomic weight, in combination with meansfor initiating a discharge through said device and means for delayingthe operation of said means for initiatinga discharge until saidelectrode has reached an operating temperature.

6. A gaseous discharge device comprising an envelope, electrodestherein, .one of which emits electrons when heated, means for heatingsaid electrode, means within said envelope reacting with said electronemitter to maintain it in electron emitting condition, and a mixture ofgases within said envelope in combination with means for initiating adischarge through said device and means for delaying the operation ofsaid means for initiating a discharge until said electrode has reachedan operating temperature.

7. A gaseous discharge device comprising an envelope, electrodestherein, one of which emits electrons when heated, means for heatingsaid electrode, a mixture of gases within said envelope, and means insaid envelope for maintaining the purity ofsaid gas mixture incombination with means for initiating a discharge through. said deviceand means for delaying the operation of said means for initiating adischarge until said electrode has reached an operating temperature.

8. An electric gaseous discharge device comprising an envelope,electrodes within a said envelope, one of said electrodes being capableof emitting electrons when heated, means for heating said electrode, agas of low atomic weight and given ionizing potential in said envelope,and another gas having a higher atomic weight and a lower ionizingpotential than said first mentioned gas inter- .mixed therewith, theproportion of said gas of higher atomic weight being the minimum whichwill cause the characteristic radiations of said gas to redominate'uponpassa e of an electrical g charge between said elec- Signed at Hobok enin the county of 'Hud- October, A. D. 1928.

ROY MAILEY.

son and State of New Jersey this 24th day of 4'. A aseous dischargedevice comprising an envelope, electrodes therein, one of which isadapted to emit electrons when heated,

means for heating said, electrode, and a mixture of rare gases withinsaid envelope, in

combination with'means for initiating a discharge through said device,and means for delaying the operation of said means for an envelope,electrodes therein, one of whic is adapted to emit electrons whenheated,

